Bluetooth (or other wireless) microphone for videography on iPhone 7+?

I am looking to use an iPhone 7+ to replace my current video camera (Canon XA-20). I have done filming with a couple iPhone 6+ camera, and the video quality is great for my purposes. However, I need some audio advice. I need to be able to put wireless lavalier microphones on two people and have them record onto the footage. Whether they communicate with the phone by way of bluetooth or some other wireless protocol doesn't matter, and if they use a receiver unit physically connected to the camera that is fine as well, as long as it is something I can connect to a 7+. When I look for information on this I see a lot of really cheap devices, and a lot of discussion of how the iPhone video recorder isn't compatible with bluetooth microphones. Is that the case? Can anyone suggest a good quality microphone setup to use? Thanks!